The Origins of Stainless Steel Date Back Almost 1,000 Years Earlier Than We Realised - ScienceAlert

Archaeologists have found what they think is evidence of low-chromium crucible steel in the 11th century in what is now Chahak in Iran, a long time and a long way away from the European Industrial Revolution.

Stainless steel is also known as chromium steel – it's the chromium in the mix that stops the rust – and while the earlier metal alloy isn't an exact match, it does show evidence of chromium being mixed with pig-iron in an alloy known as crucible steel.

"This research not only delivers the earliest known evidence for the production of chromium steel dating back as early as the 11th century CE, but also provides a chemical tracer that could aid the identification of crucible steel artefacts in museums or archaeological collections back to their origin in Chahak, or the Chahak tradition," says archaeologist Rahil Alipour from University College London.

While Chahak is only a small village today, numerous ancient manuscripts point to it as an important steel-making hub in the Persian era, and indeed it's the only known place in the region where crucible steel was being made at the time.